Need help drilling into outside edge of a circle

I need help! I need to drill the outside edge of a circle so the sticks are arranged like the picture. They need to be straight and at a certain depth. I can figure out the spacing, but short of doing it by hand does anyone have any suggestions? Maybe a jig. I’ll end up drilling hundreds of holes this way.

My drill press is just a 10” delta bench top. I was thinking of turning the base 90 degrees so the chuck would hang over the edge of my workbench unobstructed then building an adjustable (up and down) rotating jig. I could mount the circle I’m drilling so it lines up with the drill bit. That way I could drill stright down into the edge, rotate it to my next mark, drill again, so on and so on.

Any help would be great!

5 replies so far

Dowel drilling jig would be a way, depending on the size of your bit. Also would need a piece of scrab inbetween to match the radius of the curve. If bit and stock width are large, you could just make a custom doweling jig. With the amount of holes you are doing I would take the tool to the work.

Edit. If working with full circles, your idea of just rotating to the next hole would be good to if you want to use your DP. Most dowelling jigs go up to 3/8” or 1/2” diameters. It is probably sixes in time and effort for both set ups. Slight advantage to doweling jig if work thickness and circle diameter is not constant.

In lieu of a horizontal borer, vertical on your drill press is next best. Something like a fence/rest to suit the inside radius of each arc. Bore into the fence and mark the center, line up the marks on your arc with the mark on the fence, set a depth and bore. The fence would have to be lined up radial to the bit. I would think the fence would only have to be about 10in long for the small arcs add a bit for the bigger ones.

That would be the way to do it. Turn the base 90 degrees and remove the table. Screw a board to you workbench directly in line with the chuck. Then screw the plywood to the board loosely in the center so you can rotate it and drill away.

-- Steve, Webster Groves, MO "A society grows great when old men plant trees whose shade they know they shall never sit in."

Make a sacrificial plywood board to locate a pivot point on then use clamps to hold the workpiece to it so that the pivot point is in the center of the radius.

Attach a long board to the pivot point that extends 2-3 inches past the workpiece. Use a drill press to make a perpendicular hole in a 2-3 inch thick block of dense wood like hard maple. Attach that block to the board that is attached to the pivot point so that it is exactly tangent to the curve of the workpiece.

Take the drill bit that will be used to drill the holes and use a stone, or sandpaper to round over the sharp edges of the flute. This will allow you to use the wood block as a drill guide with less risk of widening the hole. Chuck the bit into a drill then carefully slide it into the hole until it bottoms out. Drill the hole.